In the manufacturing of integrated circuits and other semiconductor devices, the circuits and devices must be tested in order to ensure that a functional device has been manufactured. These tests are usually performed by contacting a test probe card to the relevant areas of the semiconductor device, and performing one or more functional tests. Two main types of probe cards are currently used to make these connections.
FIG. 1 illustrates a plan view of one type of probe card 100 that is used to test a semiconductor device (not shown). This probe card uses a series of cantilever connectors 101 that radiate inward from the edges of the probe card 100. When the probe card 100 is lowered onto the semiconductor device to be tested, the cantilevered connectors 101 connect to corresponding contact pads on the semiconductor device to complete the electrical connections for the test. Unfortunately, this type of probe card 100 is limited due to the fact that the contact pads are limited to the peripheral of the semiconductor device to be tested, and it cannot reach contact pads located in the central areas of the devices.
FIG. 2 illustrates a cross section of a portion of another type of probe card 200 which uses a array of electrical connections 201 in order to connect to a semiconductor device (not shown) in areas other than the periphery. In this type of probe card 200, the electrical connections 201 are spaced closely together in an array, and are shaped so that the electrical connections 201 absorb some of the shock of the impact when the probe card 200 is lowered on to the semiconductor device to be tested. However, the minimum pitch (the distance between the electrical connections 201) for this type of card is limited by the structure and shape of the electrical connections 201 and the current finest pitch attainable with this type of probe card is about 175 μm.
Unfortunately, as the dimensions of semiconductor devices are reduced in the ever-present drive for smaller and smaller devices, these types of probe cards will be unable to adequately test semiconductor devices requiring a smaller probe pitch. Accordingly, a probe card with a smaller probe pitch is needed.